do not put +/-Inf or NaN values into the stats map

index/store/metrics/util.go

@@ -3,6 +3,7 @@ package metrics
 import (
 	"fmt"
 	"io"
+	"math"
 
 	"github.com/rcrowley/go-metrics"
 )
@@ -18,30 +19,48 @@ func TimerMap(timer metrics.Timer) map[string]interface{} {
 	t := timer.Snapshot()
 	p := t.Percentiles(timerPercentiles)
 
+	percentileKeys := []string{"median", "75%", "95%", "99%", "99.9%"}
 	percentiles := make(map[string]interface{})
-	percentiles["median"] = p[0]
-	percentiles["75%"] = p[1]
-	percentiles["95%"] = p[2]
-	percentiles["99%"] = p[3]
-	percentiles["99.9%"] = p[4]
+	for i, pi := range p {
+		if !isNanOrInf(pi) {
+			percentileKey := percentileKeys[i]
+			percentiles[percentileKey] = pi
+		}
+	}
 
+	rateKeys := []string{"1-min", "5-min", "15-min", "mean"}
 	rates := make(map[string]interface{})
-	rates["1-min"] = t.Rate1()
-	rates["5-min"] = t.Rate5()
-	rates["15-min"] = t.Rate15()
-	rates["mean"] = t.RateMean()
+	for i, ri := range []float64{t.Rate1(), t.Rate5(), t.Rate15(), t.RateMean()} {
+		if !isNanOrInf(ri) {
+			rateKey := rateKeys[i]
+			rates[rateKey] = ri
+		}
+	}
 
 	rv["count"] = t.Count()
 	rv["min"] = t.Min()
 	rv["max"] = t.Max()
-	rv["mean"] = t.Mean()
-	rv["stddev"] = t.StdDev()
+	mean := t.Mean()
+	if !isNanOrInf(mean) {
+		rv["mean"] = mean
+	}
+	stddev := t.StdDev()
+	if !isNanOrInf(stddev) {
+		rv["stddev"] = stddev
+	}
 	rv["percentiles"] = percentiles
 	rv["rates"] = rates
 
 	return rv
 }
 
+func isNanOrInf(v float64) bool {
+	if math.IsNaN(v) || math.IsInf(v, 0) {
+		return true
+	}
+	return false
+}
+
 func WriteTimerJSON(w io.Writer, timer metrics.Timer) {
 	t := timer.Snapshot()
 	p := t.Percentiles(timerPercentiles)